I did a tube-MOSFET hybrid amp, and ran the output Mosfet as a class A follower with a CCS biased at 12Volts across the stack at 200ma. I increased the output bias and it would drive a 8ohm speaker.... backed it down to 200ma for headphone use.
Verify the output current drive on the Opamp, you would want around a 8 volt swing at 125ma or more....
Verify the output current drive on the Opamp, you would want around a 8 volt swing at 125ma or more....
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Really thanks for sharing Roline < The amp looks really good at all, but i wanna to use 6418 to drive a headphone via transistor. The reason is that i wanted to use it in hand carry(out door) beside of indoor using.
6418 is a really small tube with a fm 1.25V and 0.01A, max. P is about 30V, 0.5mA
OR a tube 6519 fm 1.25V, 10mA max. P is about 30V, 0.6mA
Would you have some ideas in this too?< Hope you can help@@ THZ
6418 is a really small tube with a fm 1.25V and 0.01A, max. P is about 30V, 0.5mA
OR a tube 6519 fm 1.25V, 10mA max. P is about 30V, 0.6mA
Would you have some ideas in this too?< Hope you can help@@ THZ
Really thanks for sharing Roline < The amp looks really good at all, but i wanna to use 6418 to drive a headphone via transistor. The reason is that i wanted to use it in hand carry(out door) beside of indoor using.
6418 is a really small tube with a fm 1.25V and 0.01A, max. P is about 30V, 0.5mA
OR a tube 6519 fm 1.25V, 10mA max. P is about 30V, 0.6mA
Would you have some ideas in this too?< Hope you can help@@ THZ
That design does not look very good. At first glance R3 and R4 seem way too large. I don't think you can run two filaments from the same supply without getting a lot of crosstalk between the channels.
If you want to drive headphones with just a transistor take a look here HeadWize - Project: A Class A MOSFET Headphone Driver by Greg J. Szekeres
Thanks astouffer< the site you posted can be used for an example.
The schematic is not my design, this is come from a kid, as you said some of the resistor might to high(This may be because the kid act the 6418 as pre-amp? and the op amp as the output?) So i am thinking use the 6418 tube as the op amp and replace the original pre-amp into transistor.
The schematic is not my design, this is come from a kid, as you said some of the resistor might to high(This may be because the kid act the 6418 as pre-amp? and the op amp as the output?) So i am thinking use the 6418 tube as the op amp and replace the original pre-amp into transistor.
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